Something like this...
web server = x.x.x.x
sql server = y.y.y.y
inside network = z.z.z.0
access-list dmz permit tcp host x.x.x.x host y.y.y.y eq 1433
access-list dmz deny ip any z.z.z.0
access-list dmz permit ip any any
access-group dmz in interface DMZ
You may also need...
static (inside,DMZ) y.y.y.y y.y.y.y netmask 255.255.255.255
Post a config if you have troubles.
